The present invention relates to a method of processing a cassette containing an X-ray film coated with a layer of stimulatable phosphorus.
Cassettes processed in the method of the invention are normally comprised of two parts pivotally connected relative to each other, namely a bottom portion accommodating a film and a lid. The layer side of the X-ray film faces the bottom of the cassette whereby when the film is exposed to X-rays a latent image produced in the reading station, after the film has been removed from the cassette, by a laser beam scanner is brought to luminescence and the emanated light would convert the latent image into digital electric image signals. Then the film is erased by exposure to visible light while digital signals are stored in a central memory and are converted into a visible image on the image screen and/or the screen image in the image screen receiving apparatus, or the digital image signals are received in the laser beam receiving apparatus controlled by the central memory (both devices are known as hardcopy devices) on a photographic sheet film.
The invention also relates to a reading station for carrying out the process of the invention.
A cassette processed in accordance with the inventive method has been disclosed, for example in EP 0,079,557 B1. A method for using such a cassette has been disclosed, for example, in EP 0,142,709 A2. Devices for carrying out the known method are available on the market. The method for processing such cassettes for accommodating films coated with a layer of phosphorus is based on the principle that the illumination of the film positioned in the cassette with X-rays results in a latent image. After the removal of the film from the cassette in the reading station, the latent image by means of the laser beam scanner becomes luminescent (phosphorus is stimulated) and the emitted light converts the image into digital electric signals indicative of that image. These signals are then again converted into a visible image on the screen or processed in a computer-controlled laser beam receiving apparatus into an image visible on the screen of that apparatus. The latent or stimulated image is then erased from the film and the film is transported into a cassette-loading device. Identification data must be provided on the film, which data can be easily read-out in a specific reading device. These data should be converted into electric identification signals and added to aforedescribed digital image signals.
The disadvantage of the known method resides in that the film, between its removal from the cassette in the reading station and its re-insertion into the cassette in the cassette loading device, is not protected against mechanical influences which can cause a premature wear-off of the phosphorus layer.